1. Field of the Invention
This invention generally relates to a pointer positioning device and method, which utilizes an image sensor integrated with an optical filter for sensing signals of a predetermined spectrum generated by an auxiliary point for positioning an aiming point of the image sensor on a display screen.
2. Description of the Related Art
A conventional pointer positioning device is disclosed in Taiwan Patent No. 1232769 entitled “A vision feedback system utilized in ray gun”. It is utilized for extracting optical point signals or optical coordinate signals sent from a ray gun to a video game system. A control circuit calculates optical point coordinate signals according to horizontal and vertical synchronizing signals of video signal and sends information of the calculated optical point coordinate signals to an image synthesizing circuit so as to synthesize the cursor aimed by a ray gun onto a corresponding scan point of the screen. In practical use, the above mentioned method has to cooperate with synchronizing signals of image display so as to perform cursor positioning thereon. However, in an image display without synchronizing signals, e.g. a liquid crystal display (LCD), a plasma display panel (PDP) and a projection screen, the cursor positioning function can hardly be performed through this method. Therefore, the above mentioned method has the problem of being limited to the image display having synchronizing signals.
Another pointer positioning apparatus and method is disclosed in Taiwan Patent No. 588258 entitled “A photographic pointer positioning device”. It utilizes a photographic pointer positioning device to process the image out-line so as to obtain coordinate values of four corners of display area, and then obtain the coordinate values corresponding to the aiming point of a video camera by coordinate calculating process so as to replace the method of obtaining the coordinate values of the aiming point by aiming point signals and synchronizing signals utilized in the traditional light gun system. In practical use, although the method can be applied to any types of image display for playing shooting game with the photographic pointer positioning device not being limited by the type of image display, the image recognition process of the display area detected by video camera is still complicated. The video camera has to detect the whole display area no matter which point is aimed by the photographic pointer positioning device, therefore the method still has the problem of needing a video camera with large viewing angle.
Another pointer positioning system is disclosed in US Patent Publication No. 2005/0107160A1, entitled “Photographic pointer positioning system and its operation process”. Although one reference signal is added to facilitate the processing of the image signal processed by an image processing unit, the aforementioned problems, i.e. difficult to recognize image display area and need a video camera with large viewing angle, are still left unsolved.
In addition, when an image sensor is utilized to photograph an image area, the photographing distance of the image sensor from the image area and the rotating angle of the image sensor during photographing may affect the positions of images formed on the sensing array of the image sensor. If it is not adjusted, an error positioning of the aiming point may occur.
Accordingly, it is necessary to further improve the above mentioned pointer positioning device and method, such that the pointer positioning device can be applied to any type of display device, the positioning accuracy can be increased and the viewing angle of the image sensor can be reduced.